In-service environmental performance - buildings
In commercial buildings, concrete offers a pleasant, comfortable and secure working environment, with suitable lighting levels and thermal control combined with the design and construction requirements of the building’s structure and external envelope. A well-designed concrete building frame will have the flexibility for multiple changes in use during its lifetime. For further information see Concrete and the Environment, published in CONCRETE in September 2001, pp39–46. Copies are available as a free download from the Members Area of the Concrete Society web site.
Economy in construction and use should not be interpreted as a financial cost, important though that is, but in environmental terms by considering the ‘life-cycle analysis’ of the structure.
Artificial lighting, computers and office equipment generate heat and may cause offices to overheat during the working day, especially in summer. If air-conditioning is provided to maintain comfort, the energy consumption of the plant is high, with consequential environmentaleffects.
The high thermal capacity of concrete buildings can be used to minimise the need for air-conditioning by reducing the thermal load. Heat exchange can be maximised by using coffered concrete ceilings with a larger surface area than flat slabs. Nocturnal ventilation can be employed to cool the structure, providing a cooling reservoir the following day.
Naturally ventilated commercial buildings typically consume half the energy used in air-conditioned buildings. Initial capital costs are typically reduced by 15% and operating costs (in terms of energy) can be 40% lower. CO2 emissions are significantly reduced. Maintenance costs are less, and a smaller proportion of the building space is occupied by plant rooms and services distribution.
Further detailed guidance on making use of the thermal mass of the building may be found in Utilisation of thermal mass in non-residential buildings
by Tom de Saulles, published for The Concrete Centre by The Concrete Society. This gives guidance on system design, floor types, surface finish and the integration of services.